1. Field of the Invention
The present invention generally relates to an interface system, and more specifically, to a multi-protocol serial interface system comprising a field protocol gate array (hereinafter, referred to as “FPGA”) to variably change roles of port pins connected to an external system in transmission/reception of serial data, which is applied in common to different types of serial communication.
2. Background of the Related Art
In general, various transport protocols such as a universal serial bus (hereinafter, referred to as “USB”) method, an ISO standard smart card method and etc. have been used in a serial data transmission/reception method. Each protocol having different roles interfaces with the external system through differently arranged port pins to transmit/receive data.
FIG. 1 is a diagram illustrating arrangement of port pins according to a USB method in the prior art.
In a USB method, a port pin array 10 comprises a VCC pin 12 for power supply, a GND pin 14 for ground, and D1 and D2 pins 16 for exchanging data. Each pin is connected through a port pin bus 18 to a corresponding terminal of a USB protocol processor 20.
FIG. 2 is a diagram illustrating arrangement of port pins according to an ISO standard smart card method in the prior art.
In an ISO standard smart card method, a port pin array 30 comprises a VCC pin 12 for power supply, a GND pin 14 for ground, a RST pin 32 for reset regulation, a CLK pin 34 for a clock pulse and an input/output (hereinafter, referred to as “I/O”) pin 36. Each pin is connected through a port pin bus 38 to a corresponding terminal of an ISO standard smart card protocol processor 40.
However, in systems to which different kinds of transport protocols are applied, other pins than the VCC pin 12 for power supply and the GND pin 14 for ground have different roles, and the arrangement of the pins is different.
Therefore, each of the conventional systems comprises an exclusive processor for processing only a protocol corresponding to a port pin array which is suitable for the applied protocol. As a result, in order to process a plurality of protocols, the system requires a plurality of processors for processing each protocol and a plurality of port pin arrays corresponding to each protocol. Additionally, the manufacturing process of the conventional system was difficult and the manufacturing cost was high.